Kinetic torsion testing machine



April 1953 F. w. DIETSCH ET AL 2,633,742

KINETIC TORSION TESTING MACHINE Filed Sept. 5, 1951 3 Sheets-Sheet l 21 30 6 6 21 l I I I s1 F l llll FIG. 3

INVENTOR. FRANCIS W. DIETSCH. C. WALTON MUSSER. ALBERT u]. sTo'r'r.

ATTORNEYS 3 April 7, 1953 F. w. DIETSCH ET AL KINETIC TORSION TESTING MACHINE 3 Sheets-Sheet 2 Filed Sept. 5, 1951 INVENTOR.

April 1953 F. w. DIETSCH ET AL 2,633,742

KINETIC TORSION TESTING MACHINE Filed Sept. 5, 1951 3 Sheets-Sheet 3 ELECTRW INVENTOR. FRANCIS w. DIETSCH. c.wA u m f R. ALBE BY W,d.l4h@ar M h. J. 5 010104441 ATTORNEYSI have long sought for a kinetic torsion machine which would enable them to follow closely the behavior of a torque and the specimen to which it was applied during the entire duration of the test. With our inventive kinetic torsion testing machine, it is now possible to know the magnitude of the applied torque, the energy expended on the specimen, as well as the torsional deflection of the specimen at any interval of time during the test. From this and subsequent explanation, it will be apparent that we have eliminated the undesirable attributes of prior art machines, and have introduced to the art inventive concepts not heretofore known.

In our novel kinetic torsion testing machine a uniquely shaped test specimen, later referred to, is accommodated throughout its length in a rotatable armature so that the specimensaxis is.

substantially congruous with that of the -armature. One end of the specimen is rotatably driven by the armature and the other end is supported in, but locked against rotation,'in'relation to a collar which rotatably and concentrically floats in the armature. By separate clutching means this sleeve can be rotatably locked or unlocked at will. By this arrangement, the collar is capable of rotating or not rotating independent of the armatures rotation.

In using our machine, a flywheel attached to the specimen-containing armature, and having a unique block pattern upon its periphery, is caused to rotate at a predetermined initial velocity. This velocity can be accurately determined, without consuming energy from the machine, by the use of stroboscopic light directed upon the fiywheels block pattern. The nature of this pattern, when viewed in the stroboscopic light, supplies a readily interpreted index of the flywheels rotational velocity.

Torsional impact is applied to the axially rotating test specimen by abruptly arresting the rotation of the specimen collar containing one end of the specimen by means of an axially sliding clutch member. However, the armature, its attached parts, and the flywheel continue to rotate. This clutch member is provided with a spline-engaged dog and is so rotatable, by the energy transmitted to it by the specimen, that the dog moves against a plunger. The plunger, in turn, presses against a calibrated piezo-electric gage where an electrical potential is established. This potential is proportional to the pressure exerted by the plunger on the piezoelectric sage and is fed, by convenient wiring, to an oscilloscope where it effect on the oscilloscopes electron beam is readily observed by the nature of the tracing on the oscilloscopes screen. The trace made by the electron beam can be generated against a background of horizontal and'vertical ordinates so as to produce a torque vs. time curve Which later can be analyzed and evaluated.

After failure of the specimen, the residual velocity of the flywheel is again noted by observing the appearance of its block pattern under stroboscopic light as earlier explained.

If desired, high speed photographic equipment 'can'be trained on the flywheel and on the oscilloscopes screen in order to' preserve, on film, a pictorial record of the actions occurring during the test.

In view of the above references to the prior art and our novel device, certain objects of our present invention will become apparent. For example, one object of our invention is to provide 4 a kinetic torsion testing machine in which the specimen to be tested is not preloaded by clamping or other means of placing it into testing position in the machine.

Another object is to provide a kinetic torsion testing machine in which both ends of the specimen are supported in alignment with each other at all times.

Still another object is to provide a kinetic torsion testing machine in which there is line contact and universal-joint action between the machine and the ends of the specimen.

Yet another object is to provide a kinetic torsion testing machine having stroboscopic means for determining theinitial and residual velocities of the machines flywheel in order to determine its loss of energy during the test.

A further object is to provide a kinetic torsion testing machine having piezo-electric means for determining the character of the torsional moment applied to the specimen, and the amount of flywheel energy absorbed by the specimen, at any instant during the test.

A still further object is to provide a kinetic torsion testing machine in which the specimen is subjected only to torsional stress and strain.

The foregoing and other objects and advantages of our invention will become apparent from an inspection of the following description and the accompanying drawings wherein:

Fig. l is a top plan view of our testing machine and auxiliary electrical equipment associated therewith;

Fig. 2 is a side view of our kinetic torsion testting machine, the electrical accessories associated therewith having been removed;

Fig. 3 is a developed view of the periphery of our machines flywheel, showing the nature of a block pattern thereon;

Fig. 4 is a sectional view of our machine taken along line 4-4 of Fig. 1 and showing, in particular, interior structural details thereof. Note that an ejector rod, not shown in Fig. 1, has been incorporated at the left portion of this figure;

Fig. 5 is an end view of our testing machine taken along line 5--5 of Fig. 2;

Fig. 6 is a vertical cross section taken alon line 6-6 of Fig. 2 and showing the adaption of a piezo-electric measuring means to our machine;

Fig. '7 is a vertical cross section taken along line 1-1 of Fig. 2 and showing a clutch release mechanism associated with our machine;

Fig. 8 is a vertical section taken along line 8-8 of Fig. 7 and showing further details of the clutch release mechanism; I

Fig. 9 is a schematic representation of the reversible electric motor and wiring therefor used in our novel machine;

Fig. 10 is a view of an aligning blade used in our testing machine. Because of the blades length, portions thereof have been removed between the break lines; and

Fig. 11 is a vertical cross section taken along line I ll I of Fig. 10 and showing further details of the aligning blade.

To facilitate a full comprehension of the construction and use of our novel machine, which is a preferred embodiment of our inventive concepts and has been chosen for illustrative purposes only, the remainder of this description will be divided into convenient headings under which pertinent components of the machine will be presented. Following presentation of the machine's components, the collective co-functioning thereof will be given.

; Base, base block, cover plates, cover sheet As shown in Figs. 1, 2,4, and 5, ourmachine consists of a base l3 in which are mounted the electric switches l4 and I5. Secured to the central portion of the ba-se upper surface in any convenient manner (not shown) is a base block I6 (see Figs. 2, 4, and to which parallel, aligned end plates l1 and I8 are secured in opposed, spaced relationshipas by screws I9 (see Figs. 4 and '5) Each end plate, as shown in Fig. 5, has the straight verticalsi-des 20 and a rounded upper portion 2|. r

- Affixed the straight sides of end plate I1 and I8, andto the base block I6 as by Screws 22,are'

window 3|, is secured in an opening in the cover.

sheet in any convenient manner as by rivets 32. More details about this window will be given later. H

' Motor, armatura-specimen drive plate, specimen V v a r Y collar, eiector rod Secured to end plate [1, as by screws 35, is a reversible electric motor 36 having the armature 31 (see Fig. 4) whose direction of rotation is so controlled by switches l4 and I5 that depression of'switch I 4 causes counterclockwise rotation of the armature (as viewed in Figs. 5, 6, and 7) and depression of switch l5 causes clockwise rotation of thearmature (as viewed in the same figures). As shown in Figs. 1, 2, and 4, the left end of the armature projects somewhat beyond the motors housing, in which it is rotatably supported in any convenient manner, and is provided with a knob 3: 8'whic'h is secured thereon by means of a set screw .39. The right end of the armature, as

shown in Fig. 4, passes through an opening in end' plate [1 whereit is rotatably supported by the bearing 42 and extends almost all thewa'y across the space between end plates l1 and I8. As also shown in that figure, the right endgof this armature is oi? unique construction and can be seen to comprise a hub 43 having thefl'ange 44. The hub has' a stepped axial recess 45 in the inner, smaller portion 'of. which is mounted, in any'convenient'manner as by screws (not shown) and dowels 46, a specimen drive plate 41 (see Fig; 4). The outer, larger portion of the stepped axial recess accommodates bearings v 48 which are mounted upon and rotatablysupport a specimen collar 49; As is usual practice, these bearings are separated by a spacer 50 which also is mounted on the specimen collar. The bearings and spacer are secured in place by means of the snap ring 5|. Extending from the bottom of stepped axial recess 45 to the armaturesleft end is an axial opening 52, which slidably accommodates amanually 'in'ser'table and removable ejector rod 53 having the knob 54. This rod is sufiiciently long to extend through the machine when fully inserted therein, but, for convenience of drawing, a portion of its length has been removed as indicated in Fig. 4. v Q Specimen drive plate 41, as shown in Fig. 4, is provided with a central cylindrical opening 55 Y having the axially extending, oppositely located grooves-56. If-viewed fromeither end of our vma-' chine, this opening and its grooves would have the same appearance as the central opening and grooves shown in Figs. 5, 6, and 7. In fact, all of these parts will be seen to be substantially conruous when so viewed. 7 1

Specimen collar 49, which is rotatably sup ported within hub 43 in alignment with the specimen drive plate, extends to the right somewhat outside the hub (see Fig. 4) and at its outer end is provided with radially extending, saw tooth-.- like serrations 51. These serrations, as will later be shown, constitute one side of a positive acting clutch. The specimen collar, like the drive plate is'also provided with an axial cylindrical opening 58 having oppositely located grooves 59. From the description thus far it can be'seen that specimen drive plate 41 rotates'with armature 31, but that thealigned specimen collar 49 is rotatable independent of the armatures rotation. The significance of this arrangement will become apparent later.i

Flywheel and peripheral pattern Securely fastened to the armatures flange 44, as by screws 6| and dowels 62 (one of each of which is shown in Fig. 4), is a flywheel 63. Upon the periphery of this flywheel we have provided a pattern 64 comprised of alternately contrasted colored areas (see Fig. 3). From that figure it can be seen that this pattern comprises a number of circumferential rows of the alternately contrasted colored areas, as for-example black and white rectangular areas, 65 and 66, respectively. Each row contains a different number of equally spaced black areas 65, each separated by a white area 66. For example, upon examining this pattern, it will be noted that the first, or left hand, row contains twenty-four black areas. The adjacent row contains twenty-three black areas. This diminution continues in succeeding rows until the final, or right hand row, contains only eight equally spaced black areas. As will be explained later, this pattern is used in conjunction with stroboscopic light in order to determine the flywheels initial'and residual velocities. Those skilled in the art will realize that the number of rowsof alternately colored areas, and the number of equally spaced black and white areas in each row can be arbitrarily chosen, depending upon the requirements to be met. Concerning the relative lengths of the black and white areas in a direction around the flywheels'periphery, we find that good results are obtained when, in' each circumferential row, the length of the. black areas is approximately 40% of the circular pitch (i.'e., circumferential distance from one area to the next).

Window In Figs. 1 and 2 it will be noted that window3l, earlier mentioned'exposes a portionof the flywheels. pattern to view. In addition, it canbe seen that the width of the window (1. e., its dimension parallel to the machine's longitudinal axis) is substantially equivalent to the overall width of the pattern, that the lower margin (1. e., toward base I3) is straight, and that the windows upper boundary (i. e., away from base I3) has a step-like appearance. Note that each step inthe window aligns with one circumferential row of the contrastingly colored areas comprising the fiywheels pattern. Therefore, the number of steps in the window's upper boundary is equivalent'to the number of circumferential rows of alternately contrasted colored areas in the pattern.- sincethat is so, eachstepyif desii'edl can lie-identified by a number; a letter, or othercom venientmarking (not; shown") in order to recur tate determination of the fi'ywheels angular velo-'eity,. as willlater be discussed.

To further facilitate determination ofthe=flywheelsangular velocity, the angular distance (in relation to the fl'ywheels' axis of rotation) from" the bottom of the windowt'o each st'ep 'fs equivalent to' the angular pitch. of the colored areas in the respective circumferentiaf rows: 7

Clutch housing, clutch; member Accommodated in. a central opening, 1.0 inend plate. 18, to which" it seemed as by means of screws TI and dowels T21 (one ofieach. of which is showminFigi 4), isv aclutcli housingvv 13, (also see. Figs 11,2, '5, 6; and-7) This clutchjhousingaccommodates a clutchfmember 1'4 which is mount e'di therein; infaxial' alignment with. speciine'rrcol lar 49', by means ofbearings 15. These bearings are spaced by a dog 18, later tobe described, which has spline engagement with the clutch member. (see Fig. 6), and are held. in place: by means; of: avsnap ring-1:1. Asshown in Fig; 4, clutch member 14siscprovidediwith.an-axial open! ing; 18. having; the oppositely located grooves 19: Thesegrooves are-substantially-of. thesame. width and depth ast those-in specimen drive plate and. specimenrcollarlil in order; slidably. too-accommodate a; drive'p-in:61A- or 6113. transfiX-ing each end ofa testspecimenfii later. tobe described. As is: evident. from that.figure;.the axial openings inspecimen drive,-plate-:41--,1 specimen collar. 49,. and

clutchmemben M- are in alignment and of. substantially the same: diameteix.

The left end of' clutch member 14 is provided with-zen enlargedi portion a-sin which are cut radially extending; sawtooth-likeserrations 8i (see-Fig.4) These serrations, as we=will later SHORE; are engage-able withthe specimen collarsearlier named serrations 51 during operation of our:machine and'form the other side of a positive acting. clutch.

Gonfined. between the; clutch member's en I'a-rged; portion 80- and the proximal: bearing: 15 is; a coil spring 82 (see Fig. 4) Asthere shown, this; spring acts constantly 'to urge clutch member 1142i1lt0. engagement with: specimen collar 4-9; However: the; axial sliding of the r clutch: member isxcontrolledi'by means of: a. clutch. release. 83 which: will; be described subsequently.

' 'Bheu-ight end of clutchmember'H-is threaded and provided with an adjustably' positioned stop collar 85%which: is held; inplace bymeansnf the seiiscrew-"ilfi (see Fig. 4 Also threadedly engaged upon the clutch member's right end is: the jack knob 81 whose purpose will become apparentlaten.

During; the. use of. our kinetic torsiorr't'esti'ng machine; clutchmember M is capable of sliding axially from leitto right, or vice versa (see Figs. 1,.2,-,.and 4.); Whenin the left hand, or engaged position, (not. shown) its saw tooth-like serrations 81. matewith serrations, T in'specim'en coll'ar- 49;, and,. when in itsright' han'd or disengaged portion (see Fig. i), the serrations are outof engagement with the clutch collar. In addition, aswilibe. evident later, the. clutch member: and its: spline engaged. dog. are. capable of limited counterclockwise.rotation as viewed. in Figs; 5', 6;

andJL Dog; mimosa riezc-electm Oscilloswpe" Fig. 6 it can be" seen that'dos (earner mode-ted in clutch; housing-- 13; as bestshowrr in Fi'gsi. 4 and 7; so that" its axis mentioned) has: a lug 'one' face 'Bl ofwhich extendsvertically above the axis-of clutch'member 14: and in. contact. with: the inner end of; av plunger-9 l slidably accommodatedinclutchhous ing 13. The opposite. face of this lug rests. against. a. set screw 89 which is threadedlv'positionedrins-clutchhousing 13. The axisof plunger 92,. as shown in Fig. 6,; is substantially perpendicular toface 9| ofthe dog The. outer endot. the: plunger restsin co'ntact with a calibrated piezo-electric gage 9.3, which; accommodated ina housing 54 threadedly connected to the. clutchhousing (alsosee.-- Figsh- 1,; 2;. and. 5) By. means of. suitable-wiring 95. ('seeFig; 1.); electricalpotem tials generated-inthepiezo-electricgage. are led.- from-its contacts.;9.6-and;;91(see Fig. 2) tda n oscilloscope; 98;- where; theirv magnitude; is; clearly indicated-onits screen-99.

Clutch reiease Clutclr release 8-3 is shown inFigsz-l 2,; 4 5%,. 7', ands: Thi'sirelea'see consisting of a knobbed por tion i0 0 and at -shank I0 4"; is rotatably" accom- It is positioned,

is perpendicular andtangentto clutch member 7 41 I The: clutch: releases -shanl l'fl l is provided with a flat I02 which, when in the horizontal position (seeFigsv 7- and. 8 willallow' the clutch member to slide. either wayi in. an axial direction above it. When this same flat is in other thana" horizontal position, (e. g." as' in Fig." 4), the -clutch= member isrestrained from engagement withspecimen collarA'Bi Clutch release 83 is rotatably secured inposition in the clutch housing by means of the stop screw I05 which isthread'edly 'attachedf to" the right endoftliehousingisee Figs: 1 and*8'-)i The inner tip [06 0f tliis'stopscrew engagesa" groove I01 (see-Figs. 7 and: 8)- which extendsfor ninety degrees in the'periplieryof" thesl'ianksknohbd portioni-Ufl. Thisst'o'p'screwthusserves the-twe fold" purpose of retaining the, clutch release and of limiting the amount of its rotation: The clutch-release, therefore; is capable'of' onl'y'ninety degreesrotation: At one: extreme, that" is; when" rotated1themaxihmm:amount in a clockwise dire'ctionas'vie'wediin Figs; 23 4; and" 8, "itis in the clutch member release'positi'on and fiat. I02 i'si'na horizontalposition (see Figs; I 7' and 81) At. the.

other extreme;,that" is when rotatedfthe' maximum am'ount'in-a counterclockwise direction as viewed in Figsuz an'd18, it i's-in' it's clutch member" blocking position; and" flat. I02, is'then a vertical. position (see; Fig. 43);

In order to accon' immiatev clutch release 83; clutch member 14" is'providediwith'a tangential fiat lfllwhich extends across the clutch member' in a direction perpendicularfto its axis. (see Figs; '4 and 7 )1 When the clutch member is in its disengaged position. this flat overlies clutch release '83 sothat the release can" be rotated tov its locking position (see Fig. 4).

Testspeczmen:

In Fig: 4 can beseen'jtest specimen- 6'8, earlier mentioned; which; is about tobetested. Notice, at the left end of the specimen, that its spherical perti'on- 69A is accommodated inthe specimen drive plate s "central cylindrical; opening '55 and that" the specimensdrive-pin- STA is-accommo dated in opposing grooves 56. At' the right end of the'specimen', its spherical' portion 69B- is accommodated in the specimen collars cylindrical axial-opening 58 and drive pin 61B is accomcanoe-74a i9 rmodated .athere .opposingigrooves -59. Thus, both aspherical ends -69A69B -.of our test specimen are supported in alignment with each other at all times :during the torsion test.

.A more detailed :description .of the uniquely shaped test specimen, per se, and-of its inventive character, will be .iound in the copending patent i-appl-icationtof Albert M.-'stOttI-fOI Static Torsion Testing Machine andfipecimen which was .filed .on June 20, 19.5.1, and bears Serial-No. 232,650.

Tubular sleeve To,facili'tateinsertion of :the testspecimen-into .ourmachine, as well-astoexpedite thespecimems removal .after completion of the torsion test, we provide .a longitudinally split, tubular sleeve .LL-l .(see Fig. 4). This sleeve .is formed .of two longitudinal halves which .fit together loosely .on the test specimen atO enclose completely the test portion-.29 thereof. Whenassembled to thespecimen, the tuhularsleeve.slidablyi-fits the cylindrical axial openings 58 and 18. When the specimen is beinginserted .into our machine the sleeve prevents the specimens .drive pins :from becoming snagged, as passing iromclutchmember M to specimen collar 49 and itrom specimen collar 49 to specimendrive plate-4,1. .A further advantage or sleeve .1 II is derived when a broken specimen is being removed atthe completion of a (test by pushing itout from the left end .of the machine 1(see Fig. 4-) by means ioi an ejector .rod 53. It is easy .tosee that, without -.our split sleeve, one broken .end of the specimen might drop down into contact with .the central openings, and dig infas it is beingpushed. Such a-condition would be especially aggravated if the clutch member were initsdisengaged position and would hinder the .specimenis removal from the .machine. This mischanoe .is obviated by :our :sleeve which allows the brokenspecimen to be pushed from the machine without difficulty.

Operation of our machine bers. spline engaged do "116 :is confined between plunger :92:and set screw 8% .(see'l ligifi). As will become apparent later in our description, this relationship between the lug, the plunger, and the :set screw :exists at all :times.

In .order to prepare :the imachine for insertion of a test specimen, :grooves 25-9 specimen collarAiSgandJgrooveS "56 in specimen drive plate 47' must be in alignment with grooves '19 in clutch member .14. The alignment of these grooves is accomplished "by :inserting our aligning blade I I5 Csee Fig. 10') into the clutch member s grooves 19, and "pushing the blade toward .thespecimen drive plate until a mark i Mi on the aligning'blade is :in registry with .the'rightend of clutch :mem-

.berl 'd. Full insertion of the aligning blade may be :ifacilitated 'by manually rotating armature .3? and :its contained specimen collar 4.9 :inxe'ither direction by nieansof hand .knob 38. When .mark 311 6 :on the aligning blade registers with the .ment with specimen tcollar 49.

16 rightendiof the clutch member, vit indicates that .allopposing grooves are .in alignment with each otherand the machine is ready for insertion of the test'specimen.

.The .aligning blade is then removed from the machine and the specimen, together with split sleeve 1H, is inserted into the clutch member's axial opening l8-so that the specimensdrive pins engage withfgrooves 79. .Again thealigning blade is inserted into the .clutchmemberand is pushed toward the left as far as the blade will go, mov- .ing the specimen before it toward specimen drive plate 41. When the test specimen is properly positioned in our machine .(see Fig. 4),,

" :thespecimens left-end abuts the bottom .of the armatures recess 45 thereby preventing further insertion, its spherical portion -:6 9A therebeing ac- .oommodated. in the drive "platefs .central opening 55 and =-its=corresponding :drive pins 61A beingacicommod-ated in the drive ,plate?s grooves 56. At the :same time, spherical portion 69B ofthespecimoms might .end is accommodated in the specinnen collars axial opening 58 and itsdrive pins 61B are-accommodatedin the collars grooves .59.

; 'F'ull :insertionof the .test specimen into our .ma-

chine is indicated when a second mark H1 on the aligning ibla'de (see Fig. -10) registers with the trightend of .clutch member 14. After therspecimenisgproperly located in themachinathealign- .ing blade :is withdrawn and the actual test can be conducted in the following =manner.

Electric switch M is depressed, thereby energizing motor 36 and causing armature 3-1, flywheel 63,,' and test specimen =68 to :revolvein 30011111181"- 4 :clockwise direction as viewed from the machines right end .seelFigs. 5 to 17).. With this direction :of rotation, black and whiteareas, =65 andlili, respectively, on the periphery of the flywheel will pass window 31 traveling insadirectiontrom top to bottom, as viewed in Fig. 2. Switch 14 is held depressed until the .armature has accelerated .to the initial angular velocity desired for thetorsion test. This velocity is accurately determined in well .known fashion by observing .the appearance of the flywheels pattern in stroboscopic light as .it moves past the window. This light emanates from a .stroboscope M2 which, it is assumed, :has been properly connected through its leads M3 and M4 to .a .suitable source of electric :POWBI (notshown-l.

When the motor has reached the initial velocityzdesi-red -for the torsiontest,electricswitch TIA is released, thus .deeenergizing the motor. However, the armature, the contained test specimen, and the attached flywheel continue to rotate'at substantially the same initial velocity. In order rsuddenl-y to -.apply the kinetic energyof our .machine to the test specimen, clutch release 83 is revolved its iull extent in a clockwise direction as viewedin Figs.:-2 and-4. Thisaction rotates the releases lflat H32 into parallelism with the a-xisof clutch member M and thereby removes the .re- .straintfrom the clutch member so that it .is immediately urged by coil springtZ into engage- As soon as the clutch member is free of restraint by the clutch release, the :clutchmember and its spline engaged dog ifisee Fig. 6) are freefer limited rotation so that the dog moves against plunger 92. The zplunger, in turn, presses against piezo-elec'tric :ga'ge :93 thereby generating an electrical potential across .it

When the clutch member is engaged with the specimen :col1ar,'-the full torquesgenerated by the machine is exerted -.on the test "specimen. The

right end of the specimen is restrained from free rotation only by its indirect connection to plunger 92 which, as shown in Fig. 6, is restrained from outward movement by piezo gage 93. From this explanation it can be seen that the torque on the specimen is exerted on the piezo gage. The electrical potential thereby generated is fed to the oscilloscope where its magnitude can be determined from the character of curve there produced upon the oscilloscopes screen.

While clutch member 14 is engaged with rotating specimen collar 49, the tendency is for the clutch member to be rotated in a counterclockwise direction, as viewed in Figs. 5 to 7, along with the specimen collar. This tendency is by virtue of the drive pin connection between specimen drive plate 41 and the left end of the test specimen, and by virtue of the similar drive pin connection between specimen collar 49 and the right end of the specimen (see Fig. 4). However, rotation of clutch member M in a counterclockwise direction (as viewed in Figs. 5 to 7) is restrained by plunger 92 which is confined between face 9| of the clutch members dog 16 and the piezo-electric gage 93. Therefore, the torque applied to the specimen is relayed to the plunger which is urged with proportional pressure against the piezoelectric gage. The electrical potential generated across the piezo-electric gage is transmitted, as earlier mentioned, through convenient wiring to an oscilloscope Where its magnitude is depicted according to its effect on the oscilloscopes electron beam.

The restraint against rotation of the specimens right end, in contrast to continued rotation of its left end by virtue of rotation of the machines armature, naturally results in torsional deflection or twisting of the specimen. The energy required to twist the specimen is derived from the flywheel and other attached parts whose velocity is correspondingly reduced. Variations within the physical properties of the specimen cause a change in torque. The change in torque applied through the specimen reflects in a change in potential across the piezo gage. This change across the piezo gage is transmitted to the oscilloscope and also is registered upon its screen.

From .this explanation it will be evident that the verticalsweep of the oscillographs electron beam will be influenced proportionally by the electrical potential generated from instant to instant in the piezo=electric gage; and the trace produced upon the oscilloscopes screen by its electron beam will indicate the magnitude of that potential. In other words, the trace will be an electrical representation of the torque applied through the test specimen from the instant of its inception to the final instant of its application thereto. This trace, as is well known, can be generated upon a background of co-ordinates in which the ordinates may represent torques applied to the specimen, and the abscissae may represent time or duration of application of the torque. By the use of suitable photographic equipment (not shown), the oscilloscopes trace, which constitutes a torque Vs. time curve, can be reproduced on film so that a permanent record of the curve is made available for subsequent analysis or reference. By means of well known formulae, this curve can be interpolated in order accurately to evaluate the magnitude of the torque applied to the specimen, or the amount of energy consumed at any time interval during the test. In addition, torsional deflection of the specimen can be determined by photographing the flywheels pattern by means of a'hlgh-speed camera (not shown). By noting the number of areas in any one row to pass window 3|, angular deflection of the specimen can easily be determined. The trace made by the oscilloscopes electron beam is influenced by the piezo-electric gage as long as there is a change of potential across the gage, or, in other words, as long as there is a torque applied to the specimen.

When the specimen fractures, as a result of being stressed beyond its ultimate torsional strength by the energy supplied by our machine, an audible sound usually is emitted. At that instant the residual angular velocity of flywheel 63 is noted by interpreting the appearance, under stroboscopic light, of its pattern 64. Again, as in the case of the initial angular velocity, tabulated information compiled for the particular pattern and range of speeds to be encountered, will enable the machines operator to determine quickly and accurately the residual velocity present in the flywheel.

Knowing the initial and residua1 velocities of the flywheel will permit the calculation, by means of well known formulae, of the torsional strength of the specimen and of the amount of energy consumed in breaking the specimen.

After failure of the test specimen, our machine can be quickly stopped in a novel and eflicient manner through the use of electromagnetic energy by depressing electric switch I5. In well known manner, schematically shown in Fig. 9, the polarity of motor 36 is reversed, and armature 31 is accordingly urged to rotate in a clockwise direction (as viewed in Figs. 5 to '7). As a result of this reversal of polarity in the motor, the angular velocity of the armature which is still rotating in a counterclockwise direction, is rapidly decelerated. Just before the armature reverses the direction of its rotation, switch I5 is released. Any remaining rotative movement of the armature can be arrested by hand.

Removal of the broken specimen from the machine is accomplished quickly in the following manner. Before proceeding, however,'it may be well to draw attention to the obvious fact that, in order to remove the broken specimen, grooves 55, 59, and 19 must be in alignment with each other, just as was necessary for insertion of the test specimen. If, by fortuitous circumstances, clutch members grooves 79 happened to align with the specimen collars grooves 59 when the clutch member snapped into engagement with the revolving specimen collar; and if specimen drive plate 47 happened to stop revolving so that its grooves 56 were aligned with the specimen collars grooves 59, the alignment depicted in Fig; 4 would exist. In that case it would be a simple matter to push ejector rod 53 into the armatures opening 52 from left to right (see Fig. 4) until the broken test specimen and sleeve Ill emerged from the right end of the clutch member.

As invariably happens, however, clutch member 14 will not engage the rotating specimen collar so that the oppositely located grooves in each part are in alignment with each other; nor will drive plate 4! generally cease rotating with its grooves aligned with those in specimen collar 49.

Therefore, prior to removing the broken specimen, the grooves in the specimen drive plate, specimen collar, and clutch member must first be aligned. To do this we have found it is first preferable to restore the clutch member to its retractedposition, thereby disengaging it from specimen :icollar Egg 4).. vBecause acoil sensin 182,, which constantly urges ,thelclutch member into engagement with the specimen colder; :is so :strong, and because it may .be awkward vnr.-.:cliffionlt,;manually to pull the clutch member Shack taraenoughiordtto-be secured in its retracted position by revolving clutch .1;elease:83, werhave provided :a :s-imple, expedient way oi rrietracting -t'he,=clutch member. To do .so it is merely necessary manuallyto rotate jack knob 81, which is threadedly engaged with :the wclutch :member; so that it moves away .from stop collar :85. @Afterca fraction Of':8;,t13l1111'1, the inner {ace -of ithe'jackhnob (i. .'e,, thatxfacertoward clutchl housing 713;). will contact the clutch housing.

Further rotation oftheilmobwillecausepthe-clutch :member to-begin, moving out-of -.engagement with spechnen-ooliarand toward the retracted ,position tseeflig. 4):. The jackzknob :is turned some more,,- f.ur.ther withdrawing the, clutch :member, uintfl'tclutchiaeleasel ififixfian be rotated .rirom ,lts

released-position, 'LShOWll' in Fig. -.8,:.to;.its locked inesition show-n inflig. 4. *When :in thelocked position, the clutchzmember has already :reached :its itetracted .yposition and is hilly-disengaged from :the-.-specimen;;collar. Before reusing :the machine, zhoweuer, slack knob {85! must be-zrotated Ibackito iits oriemalzposit-ion (see Fig. 14:) into :abutment with stop collar 8-5 :inqorder to; allow for subsequent are-engagement of the :clutch :memvI ,zber-with the specimen -.collar in-a later torsion :test. zililhis "ibacleingofi? of the jack knob can he done 58113 anyecomienient time prior to :reuse Of-1711B .nnachine.

I "i'llo'soontinue-with thesprocess-ofrrealigning:the 9 handknobu-SB ziszrotatediin eitherzdirectionzuntil the aligningblade can be moved into grooyes 59.. .lisajifinal s'tep'iin removing the broken specimen,=,ej,ector mod-53 is inserted from the left end of 'thesarmatureisraxial opening 52 (see Fig.

4) and is lightly pushed toward the right, mean while rotating the armature by "means of knob st untilrthe drive plates grooves come into ali ment with those in the specimenleollar. {When that happens,,.the Jorolcen specimen, enclosed in sleeve Hi, can be ejec'tedfrom 'the'right end of the clutch member after the aligning blade is inemovedtheref-rom.

Summary "The extent andprecision oiithemeasurenients iavailable f rom .the .use of .ourv machine are of iincaloulable .value .in the analytical study of kinetic torsion. In addition, our inventive kinetic torsion machine provides those engaged in such study with an instrument of unprecedented superiority which will, no doubt, open new avenues of approach to the solution of problems heretofore without answer.

From the foregoing it will be apparent to those skilled in the art that We have provided a kinetic torsion testing machine in which the specimen to be tested is not preloaded by clamping or other means of placing it into testing position in the machine, that we have provided a kinetic torsion testing machine in which both ends of #214 the specimen. are supported inalignment with each-- .other at. all times, that we havegproyided a ,kinetic torsion testing machine in which there -is line contact .and universal joint action between the machine and the .ends of the specimen, that we have provided a kinetic torsion testing machine having :stroboscopic means ,for determining thezinitial and residual 'velocitieso'f :the -ma,chineT-s flywheel, that we have provided a kinetic torsion testing machine havingpiezoelectric. means ,;for determining the character of the torsional moment applied .to the specimen and the amount-offlywheelenerg-y absorbed by the specimen-at any .instant during the test;

:and,=that yvehaveprovidedakinetic torsion testing machine in which the specimen vis-subiected :only to torsional :stress and strain.

Because numerous variations and ;modifica :tions :of our inventive machine are possible with- 01113 departingirom its original spirit .andscope, we do :not wishto :be limited in the protection of patent coverage *by the narrow confines 50f the single embodliment :here disclosed for illustrative purposes only, but arather, only byfthe breadth and scope :of the appended claims.

We claim:

.1. ;-A kinetic torsion :testing machine .ior canalyzing the physical properties of :anuelongated test specimen, :comprisingra base, an upright plate .:secured :to said base; :an'armaturehavingian axial :recess in one end thereof :and rotatably mounted in saidtnprighthlate ssoras to extend beyond opposite surfaces thereof, means :for roa'tating said armature, .a specimen drive plate .mouritedzin (the :axial zrecessiof v:said :armatune 'to rotate concentrically therewith, aspecimen collar rotatably :mounted in said armaturesrecess axially aligned :and juxtaposed with .said drive platetbut independentof .thedrive:platesrotation, saidnollar vremo ab-ly accommo dating therein {or :rotationttherewithsonei'endnf theelongatedspecimen to :be tested, the other :end -;of which :is :reamovably mounted *in and notatably .driVen b-ysaid drive plate, a flywheel secured to :said armature, means for iabruptly arresting the rotation of said collarr-and-sits :containedztest specimen end where- :by :to :cause .:a ltQISiiQIlfil impact to ice applied (to the test specimen :and :resnltant fracture :thereof by. the continuing rotation of saidarmatune, :its attached :drive plate and contained other end set the stESt rspecimenpandimeans for measuring the ohangerin angular velocity ojsaidfiywheel before andaiter thespecimen is ciractured so "that the specimens torsional strength and .theamonnt of energy consumed in breaking the rspecimenmay aloe determined.

.Aikinetic torsion testing :machine fier anaalyiinjgithe physioalzprepertieszof an elongated-test specimen, comprising: :a. base, an upright 11.61

"plate:seouredtonaid'hase an armature havmgzan axial recess tin one end thereof and :rotatably mollntedain upright plateso asto :extendiheyond opposite surfaces thereof, a specimen drive plate mounted in the armatures axial recess so as to rotate in unison with said armature, a specimen collar rotatably mounted in the armatures axial recess axially aligned and juxtaposed with said specimen drive plate but independent of the drive plates rotation, said collar removably accommodating thereinfor rotation therewith one end of the elongated specimen to be tested, the other end of which is removably mounted in and rotatably driven by said drive plate, a flywheel secured to said armature, a pattern of difierent colored areas on the flywheels periphery, electrically operated means for rotating said armature, a stroboscope for use in connection with said pattern to determine the flywheels angular: velocity, and means for abruptly arresting the rotation of said collar and the end of said specimen contained therein whereby to cause a torsional impact to be applied to the test specimen by the continuing rotation of said armature, the attached specimen drive plate and its contained other end of the test specimen.

3. In a kinetic torsion testing machine for analyzing the physical properties of an elongated test specimen, the combination of an armature having an axial recess in one end thereof, a specimen drive plate mounted in the axial recess of said armature to rotate concentrically therewith, a flywheel secured to said armature for rotation therewith and having an axial recess aligned with the armatures recess, a specimen collar rotatably mounted in said flywheel in axial alignment with said specimen drive plate but independent of the drive plates and the flywheels rotation, said c01- lar removably accommodating therein for rotation therewith one end of the elongated specimen to be tested, the other end of which is removably mounted in and rotatably driven by said drive plate, means for rotating said armature and flywheel together with their said contained specimen drive plate and specimen collar as well as the test specimen carried thereby, and means for abruptly arresting the rotation of said specimen collar and its contained test specimen end, whereby to cause a torsional impact to be applied to the test specimen by the continuing rotation of said armature, its attached drive plate and contained other end of the test specimen.

4. In combination, a kinetic torsion testing ma chine having a power driving source, a flywheel rotatably driven by said power driving source, a

first holding means carried by said flywheel for rotation therewith and for rotatably supporting one end of a longitudinal test specimen, a second holding means carried by said flywheel but free to rotate independently thereof and non-rctatably supporting the other end of the test specimen, a pattern of different colored areas on said flywheels periphery, means for abruptly stopping rotation of said second holding means so as to cause application of a torsional'impact to the specimen and fracture thereof as said first holding means continues to be rotated, and stroboscopic means focused on said pattern for determining the flywheels velocity before and after specimen fracture, wherebyto ascertain the specimens torsional strength.

5. In combination, a kinetic torsion testing machine having a power driving source, a flywheel rotatably driven by said power driving source, a first holding means carried by said flywheel for rotation therewith and non-rotatably supporting one end of a longitudinal test specimen, a second holding means carried by said 16 flywheel but free to rotate independently thereof and non-rotatably supporting the other end of the test specimen, clutch means for abruptly stopping rotation of said second holding means so as to cause application of a torsional impact to the specimen and fracture thereof as said first holding means continues to be rotated, a piezoelectric gage, a plunger having one end in contact with said clutch means and the other end in contact with said piezo-electric gage so that the torsional moment exerted upon applying said clutch means may be indicated by said gage, and an oscilloscope connected to said piezo-electric gage for establishing a visual record of the torsional moment exerted upon the test specimen and indicated by the gage.

6. In combination, a kinetic torsion testing machine having a power driving source, a flywheel rotatably driven by said power driving source, a first holding means carried by said flywheel for rotation therewith and non-rotatably supporting one end of a longitudinal test specimen, a second holding means carried by said flywheel but free to rotate independently thereof and non-rotatably supporting the other end of the test specimen, a pattern of different colored areas on said flywheels periphery, clutch means for abruptly stopping rotation of said second holding means so as to cause application of a torsional impact to the specimen and fracture thereof as said first holding means continues to be rotated, stroboscopic means focused on said'pattern for determining the flywheels velocity before and after specimen fracture, a piezoelectric gage, a plunger having one end in contact with said clutch means and the other end in contact with said piezo-electric gage so that the torsional moment exerted upon applying said clutch means may be indicated by said gage, and an oscilloscope connected to said piezo-electric gage for establishing a visual record of the torsional moment exerted uponthe test specimen and indicated by the gage, whereby the torsional strength of the specimen and the amount of energy consumed in effecting its fracture may be determined.

FRANCIS W. DIEISCH. C. WALTON MUSSER, ALBERT M. STO'I'I.

REFERENCES CITED The following references are of record in the file of this patent:'

UNITED STATES PATENTS Number Name Date 1,828,564 Hardesty Oct. 20, 1931 1,930,905 Nicholson Oct. 17, 1933 2,042,231 Lewis May 26,1936. 2,302,496 Gasser Nov. 17, 1942 2,415,215 Mayberry Feb. 4, 1947 2,496,420 Stern Feb. '7, 1950 

